Server systems have long utilized network switches, commonly referred to as “switches,” to serve as a central connection for network equipment and devices. Switches are able to identify a system or device connected to a particular port of the switch, and are able to filter and send data to the system or device without increasing network response times. Network interface cards (NICs) generally are hardware cards within networked devices that handle many of the technical aspects of sending and receiving packets of data, such as to and from servers. In a traditional server setup, an Ethernet cable is directly plugged into an NIC of the server device on one end, and into a port of a switch on the other end that is external to the server and NIC.
Dynamic Host Configuration Protocol (DHCP) is a network protocol that automatically assigns an Internet Protocol address (IP address) to a networked device, from a defined range of addresses configured for a given network. A server or other networked device sends a DHCP request to a DHCP server to request an IP address, and the DHCP server responds, confirming that the device has been given a lease on the IP address for a specified period of time.
In a server design in which a switch is external to the server and NIC, the server can detect a link state change of the switch, such as when a user plugs or unplugs an Ethernet cable to or from a port of the switch. The server can then instruct the DHCP client of the server to negotiate a DHCP protocol to obtain a new IP address if one is needed.